To a small electronic apparatus such as a digital still camera, a digital video camera, or a cellular phone, a battery pack for a lithium-ion secondary battery or the like is detachably attached. In the existing electronic apparatuses, battery packs are often prepared for each model and thus arrangement of terminals in a battery attachment portion varies depending on the model of the electronic apparatus. Although for example, in general, the terminals in the battery attachment portion are often arranged in an order of a plus terminal, a control terminal, and a minus terminal, their intervals or the like are different depending on the kind thereof. Thus, there are many cases where the battery pack corresponding to each electronic apparatus is not excellent in general use and cannot be attached to various electronic apparatuses irrespective of the kind of the electronic apparatus.
Further, the battery pack is detached from the battery attachment portion for charging or the like. Then, the user may accidentally drop the battery pack when attaching or detaching the battery pack to/from the electronic apparatus. Thus, the battery pack also needs a mechanical strength enough to withstand a dropping impact.